OXON HILL, Md. — The auditions have begun.

Just two months into President Barack Obama's second term, Republican leaders are lining up to diagnose the GOP's ills while courting party activists — all with an eye on greater political ambitions. They have danced around questions about their White House aspirations, but the die-hard conservatives are already picking favorites in what could be a crowded Republican presidential primary in 2016.

Thousands of activists who packed into suburban Washington's national conservative summit gave Kentucky Sen. Rand Paul a narrow victory over Florida Sen. Marco Rubio in their unscientific presidential preference poll. Paul had 25 percent of the vote and Rubio 23 percent. Former Pennsylvania Sen. Rick Santorum was third with 8 percent.

The freshman senators topped a pool of nearly two dozen governors and elected officials who paraded through the same ballroom stage over three days. There were passionate calls for party unity, as the party's old guard and a new generation of leaders clashed over the future of the wayward Republican Party.

First-term Wisconsin Gov. Scott Walker, who placed sixth in the straw poll, on Saturday encouraged Republicans to be aggressive but warned them to focus on middle-class concerns: "We need to be relevant."

Later in the day, the party's 2008 vice presidential nominee, former Alaska Gov. Sarah Palin, mixed anti-Obama rhetoric with calls for a more inclusive GOP: "We must leave no American behind," she said after likening Washington leadership to reality television.

And former House Speaker Newt Gingrich, a 2012 presidential contender, charged that GOP leadership "is as mired in past and mired in stupidity as it was in 1976."

But the ballroom stage was emblazoned with the words "America's Future: The Next Generation of Conservatives," making clear the party's interest in showcasing a new wave of talent. The gathering evoked the ending of one period and the beginning of another.

Sharp competition among Republican leadership comes as President Barack Obama's role as the head of his party is unquestioned. Even looking to the next presidential election, there is a smaller pool of possible Democratic candidates largely waiting on former Secretary of State Hillary Rodham Clinton to shape her plans. Democrats concede she would be the strong favorite to win her party's nomination if she ran.

There is no such certainty on the Republican side, regardless of the outcome of the conservative straw poll.

Several high-profile Republicans are jockeying for elevated leadership roles.

Earlier in the week, Paul insisted on a new direction in Republican politics: "The GOP of old has grown stale and moss-covered."

The straw poll victory offers little more than bragging rights for Paul, who is popular with the younger generation of libertarian-minded conservatives who packed the conference in suburban Washington. Nearly 3,000 people participated in the online survey and more than half were younger than 26.

Paul's father, former Texas Rep. Ron Paul, won the poll in 2010 and 2011, while presidential nominee Mitt Romney took the honor last year.

Rubio drew thunderous applause by proclaiming that the Republican Party doesn't need any new ideas: "There is an idea. The idea is called America, and it still works," he said in a speech aimed squarely at middle-class voters.

Walker thrilled activists Saturday by declaring: "In America, we believe in the people and not in the government."

"It is precisely why, in America, we take a day off and celebrate the Fourth of July and not the 15th of April," he said.

And former Florida Gov. Jeb Bush, perhaps the highest-profile establishment figure as the son and brother of presidents, held out the prospect of the nation's greatest century if the GOP were to evolve into the party of "inclusion and acceptance."

Louisiana Gov. Bobby Jindal urged Republicans to "recalibrate the compass of conservatism."

The Republican confab also featured Romney, who delivered his first speech since his Election Day loss four months ago.

He offered a valedictory of sorts, thanking activists for supporting his campaign, while conceding mistakes — although he didn't offer any specifics. In a nod to the next generation, he urged conservatives to learn lessons from the nation's 30 Republican governors.

Romney heaped praise on his 2012 running mate, Wisconsin Rep. Paul Ryan, while naming a handful of governors who have sought a larger national profile, including Bob McDonnell of Virginia and Chris Christie of New Jersey.

Neither Christie nor McDonnell were invited to the conference after rankling conservatives in recent months for, among other things, supporting efforts to expand Medicaid coverage as part of Obama's health care overhaul.

Most of the candidates have been working to raise their national profiles while tiptoeing around questions about their presidential ambitions.

Walker told The Associated Press late last month that a 2016 presidential bid "would be an option," although it wasn't something he was "actively pursuing."

Paul has said he's "seriously considering" running for the White House. Ryan, the House Budget Committee chairman, has avoided such questions and instead continued his central role in one of Capitol Hill's most significant policy debates.

Jindal laughed off questions about his future: "Any Republican that's thinking about talking about running for president in 2016 needs to get his head examined," he said last month. "We've got a lot of work to do."

And of course there is an even fresher crop of conservatives auditioning as well.

Ben Carson, a neurosurgeon who was critical of Obama's policies during the National Prayer Breakfast, told activists Saturday that he would soon retire from medicine and could have a future in politics.

"Let's say you magically put me in the White House," Carson said before being interrupted by cheers.

"Who knows what I'm going to do," he said.